Linux Administration

LinuxCommand.md

• Users are on the system are listed in an alphabetical order - cut /etc/passwrd -d":" -f1 | sort
• User has shell access - cat /etc/passwd | cut -d":" -f4,5,6,7 | grep "^0" or count - cat /etc/passwd | cut -d":" -f4 | grep "^0" | wc -l
• Export the Users' list to a file - cut /etc/passwd -d ":" -f1 > system_users.txt
• Count the number of Users - cat ./system_users.txt | sort | wc –l
• Compare - cat ./system_users.txt - cut /etc/passwd -d ":" -f1 > system_users002.txt && cat system_users002.txt | sort | wc -l
• Diff - diff ./system_users.txt ./system_users002.txt
• how many words begin with the letter a from the main user dictionary - egrep '^a.*$' /usr/share/dict/words | wc -l
• tee to both view and write files and directories in /etc - ls -d /etc/a* | tee ./etc_report_a.txt
• Kernel Info - lsb_release -a or uname -a or hostnamectl or cat /proc/os-release